The invention disclosed in my 1965 patent relates to a double-wall endotracheal cuff, the external wall of which is multiperforated for the administration of continuous or intermittent local endotracheal anesthesia. The very same cuff may be very advantageously employed for endo-esophageal, endo-stomach, endo-duodenal, or pharyngeal surface anesthesia as well as surface anesthesia in any other cavity in the body, as well as for other necessary medicaments.
The problem which anesthetists and surgeons have encountered in the use of endotracheal anesthesia, and which the invention of my 1965 patent solved, is that shortly (about three quarters of an hour or sooner) after injection of anesthetic into the trachea and placing of the endotracheal tube, the anesthetic wears off or is destroyed and the patient is thereafter unable to endure the presence of the tube in the trachea. The patient starts to cough and vomit, making it difficult for the surgeon to perform the operating procedure. Attempts had been made, prior to the invention of my 1965 patent, to solve this problem by use of deep anesthesia administered to such level that the patient loses all endotracheal feeling and reflexes. Frequently this unnecessarily intoxicated the whole body system and often endangered the life of the patient, especially in the presence of damage to the cardio-vascular system, liver, kidney, lungs or brain centers.
The invention of my 1965 patent is a double-wall endotracheal cuff for continuous or intermittent local endotracheal anesthesia around the endotracheal tube which enables the patient to tolerate the endotracheal tube, not only during the light-superficial stage of general anesthesia but also in the absence of general anesthesia when the patient is awake. My invention could be life saving in conditions such as tetanus or bilateral pneumonia when a continuous free passage of oxygen to the lungs and suction of exudate from the lungs represents most important factors for a succesful recovery.
While the invention of my 1965 patent was a major improvement in the anesthetic art it did not solve all of the problems. One problem which became known shortly after the invention went into surgical use was that local anesthetic injected around the wall of the outer cuff was metabolized in 45 minutes to an hour and, therefore, a new portion of anesthetic had to be administered. The additional anesthetic created the risk of oversaturating the patient. Thus, there was a long-felt need to solve this problem and its solution eluded me and others until now.